The objective of this 5-year, prospective, observational cohort study is to evaluate the long-term safety and clinical outcomes of patients with Alagille syndrome (ALGS) or Progressive familial intrahepatic cholestasis (PFIC) treated with Livmarli.

Livmarli® is a novel, minimally absorbed, pharmacological product that inhibits the ileal bile acid transporter (IBAT) in the terminal ileum, leading to reduced levels of bile acids. Livmarli (maralixibat) has been developed by Mirum Pharmaceuticals and was the first treatment approved by the US Food and Drug Administration (FDA) for the treatment of cholestatic pruritus in patients 3 months of age and older with Alagille syndrome (ALGS). Subsequently, Livmarli was approved by the FDA for the treatment of cholestatic pruritus in patients 12 months of age and older with Progressive familial intrahepatic cholestasis (PFIC). To be eligible for the study, participants must meet the following criteria:

• A clinically and/or genetically confirmed ALGS diagnosis or PFIC diagnosis
• Prescribed Livmarli

Inclusion Criteria:

• A clinically and/or genetically confirmed ALGS diagnosis or PFIC diagnosis
• Participant prescribed Livmarli

Exclusion Criteria:

• Refusal to provide informed consent/assent (if required by the local IRB)
• Previously or currently on Livmarli through participation in a clinical study or expanded access program
• Participants who have previously received an SBD or LT
• Any condition or abnormalities that, in the opinion of the investigator, may interfere with the participant participating in or completing the study
• Participants who have received an investigational drug within 30 days of the first dose of Livmarli

All patients with ALGS and PFIC prescribed Livmarli at a participating study center and who consent/assent to participation (if required by the local IRB/IEC) will be included in the study at the discretion of the center investigator.